Eyebrows are almost always raised when giants of internet and software make hardware investments. An exception to the rule happened towards the end of last week, with Baidu investing $158 million into Chinese electronics maker Skyworth Digital’s smart TV sector. What makes this stand out is the investment supposedly has a core focus on artificial intelligence rather than the TV, set top and WiFi gateway businesses Skyworth is better known for. By AI, Baidu really means voice-powered intelligence embedded into smart TVs via its own DuerOS, as China’s largest online search engine once more strengthens its position to get a foothold in a voice market which some have suggested is more competitive than the US and Europe combined. DuerOS is…